Expanded valve seat



April 15, 1930. A. H. LEIPERT EXPANDED VALVE SEAT Original Filed June 5, 1928 Mum v1 1 04/ WM .Ww2 W m5 w Patented Apr. 15, 1930 UNITED STATES PATENT OFFICE,

AUGUST II. LEIPER'I, OF COLLEGE POINT, NEW YORK, ASSTGNOR TO INTERNATIONAL MOTOR COMPANY, OF NEW YORK, N. Y., A CORPORATION OF DELAWARE EXPANDED VALVE SEAT Original application filed June 5, 1928, Serial No. 282,988.

Divided and this application filed. May 4, 1929.

Serial No. 360,361.

It has heretofore been proposed to form valve seats of metal which can be rolled into position and secured readily against displacement in order to provide a more perfect valve seat and promote the cooling thereof. It is preferable that the material of the seat be such that it can be readily rolled and fitted and it is further desirable that the heat conductivity be very great.

It has been found that the joint between the valve seat and the cylinder casting can be materially improved and the heat transfer therebetween correspondingly increased if the valve seat is formed in such manner that the engagement by the undercut seat of the cylinder casting is rendered tight both when the engine is hot and when cold. Since the valve seat is usually formed of aluminum bronze and the cylinder casting, of course, is cast iron, the coefiicients of expansion of these two metals differ and the expansions thereof vary with variations in temperature.

The present invention has for an object the provision of a valve seat which insures tightness thereof under all operating conditions, thus materially decreasing the temperature of the seat and improving the operating conditions thereof.

This application is a division of the application of August 1-1. Leipert, Ser. No. 282,988, filed June 5, 1928, for expanded valve seat and the subject matter herein embodies the seat and its mounting in the cylinder in accordance with the present invention. The invention will be understood more fully in connection with the accompanying drawings, wherein:

Figure 1 is a view in section showing the manner in which the cylinder casting is undercut to receive the seat.

Figure 2 is a view in section, taken on line 22 of Figure 3, and looking in the direction of the arrows.

Figure 3 is a plan view of the valve and seat construction shown in Figure 2.

Referring to the above drawings, the cylinder casting a is formed with an annular groove a the wall of which is undercut at a Protruding upwardly into the groove a is an annular rib a about which the valve seat is formed. In forming the seat, a recessed plate I) is bolted to the top of the cylinder casting and an annular ring of aluminum bronze 0 is placed as shown in Figure 1. A suitable expander cl is then applied to force the ring 0 into the groove a so that it fills the entire portion thereof as shown in Figure 2. Suitable notches a are formed in the cylinder casting and the material of the valve seat is forced into these, thus positively securing the seat against rotation within the groove a.

After the seat 0 has been expanded into the groove a it is heated and then expanded again. This insures the complete flowing of the metal of the seat into every recess in the groove a. If desired, the cylinder casting itself can be heated and the aluminum bronze valve seat expanded into the casting while the latter is hot, the valve seat then being re-expanded after the heating thereof.

Under operating conditions, and when the valve seat is initially heated and is expanding faster than the cylinder casting the valve seat grips against the undercut portion a of the groove a. When the valve seat is contracting it grips against the external periphery a of the rib a In this manner, the seat is rigidly held in position and movement thereof is prevented regardless of the operating conditions.

I claim as my invention:

1. A valve seat construction comprising a cylinder casting formed with a groove, an undercut portion formed in the wall of the groove, a rib protruding into the groove, and a valve seat in the groove.

2. A valve seat construction comprising a cylinder casting formed with a groove, an undercut portion formed in the wall of the groove at one side thereof, a rib protruding into the groove from a second side thereof, and a valve seat in the groove.

3. A valve seat construction comprising a cylinder casting formed with an annular groove, an undercut portion formed in the vertical wall of the groove, a rib formed on the horizontal wall of the groove and protruding thereinto, and a valve seat in the groove.

r2 Ur) 4. A valve seat construction comprising a cylinder casting formed with a groove, an undercut portion formed in the wall of the groove, a rib protruding into the groove at an angle to the undercut portion, and a valve seat in the groove.

This specification signed this 30th day of April, A. D. 1929.

AUGUST H. LEIPERT. 

